From 5da2010840a3b4d99fcdccb7cdef0ffbd6e9a29f Mon Sep 17 00:00:00 2001 From: Carlos Amedee Date: Fri, 13 Aug 2021 14:42:49 -0400 Subject: [PATCH] doc: start draft of go1.18 release notes, move go1.17 to x/website This template is based on CL 295209 and previous ones like it. Continue to eagerly include often-used sections, and clarify that the TODO is about completing the section, or removing if it turns out not to be needed. Move the Go 1.17 release notes to x/website, since that's the new home for past Go release notes as of CL 291711. They're added to x/website in CL 342089. For #47694 Updates #44513 Change-Id: I24962eed800d1509bdf71b7d7f819a683eb96f8f Reviewed-on: https://go-review.googlesource.com/c/go/+/342070 Trust: Carlos Amedee Run-TryBot: Carlos Amedee Reviewed-by: Dmitri Shuralyov TryBot-Result: Go Bot --- doc/go1.17.html | 1240 ----------------------------------------------- doc/go1.18.html | 84 ++++ 2 files changed, 84 insertions(+), 1240 deletions(-) delete mode 100644 doc/go1.17.html create mode 100644 doc/go1.18.html diff --git a/doc/go1.17.html b/doc/go1.17.html deleted file mode 100644 index c1b5ab3f6f..0000000000 --- a/doc/go1.17.html +++ /dev/null @@ -1,1240 +0,0 @@ - - - - - - -

Introduction to Go 1.17

- -

- The latest Go release, version 1.17, arrives six months after Go 1.16. - Most of its changes are in the implementation of the toolchain, runtime, and libraries. - As always, the release maintains the Go 1 promise of compatibility. - We expect almost all Go programs to continue to compile and run as before. -

- -

Changes to the language

- -

- Go 1.17 includes three small enhancements to the language. -

- -
    -
  • - Conversions - from slice to array pointer: An expression s of - type []T may now be converted to array pointer type - *[N]T. If a is the result of such a - conversion, then corresponding indices that are in range refer to - the same underlying elements: &a[i] == &s[i] - for 0 <= i < N. The conversion panics if - len(s) is less than N. -
    • - -
  • - unsafe.Add: - unsafe.Add(ptr, len) adds len - to ptr and returns the updated pointer - unsafe.Pointer(uintptr(ptr) + uintptr(len)). -
    • - -
  • - unsafe.Slice: - For expression ptr of type *T, - unsafe.Slice(ptr, len) returns a slice of - type []T whose underlying array starts - at ptr and whose length and capacity - are len. -
    • -
- -

- The package unsafe enhancements were added to simplify writing code that conforms - to unsafe.Pointer's safety - rules, but the rules remain unchanged. In particular, existing - programs that correctly use unsafe.Pointer remain - valid, and new programs must still follow the rules when - using unsafe.Add or unsafe.Slice. -

- - -

- Note that the new conversion from slice to array pointer is the - first case in which a type conversion can panic at run time. - Analysis tools that assume type conversions can never panic - should be updated to consider this possibility. -

- -

Ports

- -

Darwin

- -

- As announced in the Go 1.16 release - notes, Go 1.17 requires macOS 10.13 High Sierra or later; support - for previous versions has been discontinued. -

- -

Windows

- -

- Go 1.17 adds support of 64-bit ARM architecture on Windows (the - windows/arm64 port). This port supports cgo. -

- -

OpenBSD

- -

- The 64-bit MIPS architecture on OpenBSD (the openbsd/mips64 - port) now supports cgo. -

- -

- In Go 1.16, on the 64-bit x86 and 64-bit ARM architectures on - OpenBSD (the openbsd/amd64 and openbsd/arm64 - ports) system calls are made through libc, instead - of directly using machine instructions. In Go 1.17, this is also - done on the 32-bit x86 and 32-bit ARM architectures on OpenBSD - (the openbsd/386 and openbsd/arm ports). - This ensures compatibility with OpenBSD 6.9 onwards, which require - system calls to be made through libc for non-static - Go binaries. -

- -

ARM64

- -

- Go programs now maintain stack frame pointers on the 64-bit ARM - architecture on all operating systems. Previously it maintained - stack frame pointers only on Linux, macOS, and iOS. -

- -

loong64 GOARCH value reserved

- -

- The main Go compiler does not yet support the LoongArch - architecture, but we've reserved the GOARCH value - "loong64". - This means that Go files named *_loong64.go will now - be ignored by Go - tools except when that GOARCH value is being used. -

- -

Tools

- -

Go command

- - -

Pruned module graphs in go 1.17 modules

- -

- If a module specifies go 1.17 or higher, the module - graph includes only the immediate dependencies of - other go 1.17 modules, not their full transitive - dependencies. (See Module graph pruning - for more detail.) -

- -

- For the go command to correctly resolve transitive imports using - the pruned module graph, the go.mod file for each module needs to - include more detail about the transitive dependencies relevant to that module. - If a module specifies go 1.17 or higher in its - go.mod file, its go.mod file now contains an - explicit require - directive for every module that provides a transitively-imported package. - (In previous versions, the go.mod file typically only included - explicit requirements for directly-imported packages.) -

- -

- Since the expanded go.mod file needed for module graph pruning - includes all of the dependencies needed to load the imports of any package in - the main module, if the main module specifies - go 1.17 or higher the go tool no longer - reads (or even downloads) go.mod files for dependencies if they - are not needed in order to complete the requested command. - (See Lazy loading.) -

- -

- Because the number of explicit requirements may be substantially larger in an - expanded Go 1.17 go.mod file, the newly-added requirements - on indirect dependencies in a go 1.17 - module are maintained in a separate require block from the block - containing direct dependencies. -

- -

- To facilitate the upgrade to Go 1.17 pruned module graphs, the - go mod tidy - subcommand now supports a -go flag to set or change - the go version in the go.mod file. To convert - the go.mod file for an existing module to Go 1.17 without - changing the selected versions of its dependencies, run: -

- -
-  go mod tidy -go=1.17
-
- -

- By default, go mod tidy verifies that - the selected versions of dependencies relevant to the main module are the same - versions that would be used by the prior Go release (Go 1.16 for a module that - specifies go 1.17), and preserves - the go.sum entries needed by that release even for dependencies - that are not normally needed by other commands. -

- -

- The -compat flag allows that version to be overridden to support - older (or only newer) versions, up to the version specified by - the go directive in the go.mod file. To tidy - a go 1.17 module for Go 1.17 only, without saving - checksums for (or checking for consistency with) Go 1.16: -

- -
-  go mod tidy -compat=1.17
-
- -

- Note that even if the main module is tidied with -compat=1.17, - users who require the module from a - go 1.16 or earlier module will still be able to - use it, provided that the packages use only compatible language and library - features. -

- -

- The go mod graph - subcommand also supports the -go flag, which causes it to report - the graph as seen by the indicated Go version, showing dependencies that may - otherwise be pruned out. -

- -

Module deprecation comments

- -

- Module authors may deprecate a module by adding a - // Deprecated: - comment to go.mod, then tagging a new version. - go get now prints a warning if a module needed to - build packages named on the command line is deprecated. go - list -m -u prints deprecations for all - dependencies (use -f or -json to show the full - message). The go command considers different major versions to - be distinct modules, so this mechanism may be used, for example, to provide - users with migration instructions for a new major version. -

- -

go get

- -

- The go get -insecure flag is - deprecated and has been removed. To permit the use of insecure schemes - when fetching dependencies, please use the GOINSECURE - environment variable. The -insecure flag also bypassed module - sum validation, use GOPRIVATE or GONOSUMDB if - you need that functionality. See go help - environment for details. -

- -

- go get prints a deprecation warning when installing - commands outside the main module (without the -d flag). - go install cmd@version should be used - instead to install a command at a specific version, using a suffix like - @latest or @v1.2.3. In Go 1.18, the -d - flag will always be enabled, and go get will only - be used to change dependencies in go.mod. -

- -

go.mod files missing go directives

- -

- If the main module's go.mod file does not contain - a go directive and - the go command cannot update the go.mod file, the - go command now assumes go 1.11 instead of the - current release. (go mod init has added - go directives automatically since - Go 1.12.) -

- -

- If a module dependency lacks an explicit go.mod file, or - its go.mod file does not contain - a go directive, - the go command now assumes go 1.16 for that - dependency instead of the current release. (Dependencies developed in GOPATH - mode may lack a go.mod file, and - the vendor/modules.txt has to date never recorded - the go versions indicated by dependencies' go.mod - files.) -

- -

vendor contents

- -

- If the main module specifies go 1.17 or higher, - go mod vendor - now annotates - vendor/modules.txt with the go version indicated by - each vendored module in its own go.mod file. The annotated - version is used when building the module's packages from vendored source code. -

- -

- If the main module specifies go 1.17 or higher, - go mod vendor now omits go.mod - and go.sum files for vendored dependencies, which can otherwise - interfere with the ability of the go command to identify the correct - module root when invoked within the vendor tree. -

- -

Password prompts

- -

- The go command by default now suppresses SSH password prompts and - Git Credential Manager prompts when fetching Git repositories using SSH, as it - already did previously for other Git password prompts. Users authenticating to - private Git repos with password-protected SSH may configure - an ssh-agent to enable the go command to use - password-protected SSH keys. -

- -

go mod download

- -

- When go mod download is invoked without - arguments, it will no longer save sums for downloaded module content to - go.sum. It may still make changes to go.mod and - go.sum needed to load the build list. This is the same as the - behavior in Go 1.15. To save sums for all modules, use go - mod download all. -

- -

//go:build lines

- -

- The go command now understands //go:build lines - and prefers them over // +build lines. The new syntax uses - boolean expressions, just like Go, and should be less error-prone. - As of this release, the new syntax is fully supported, and all Go files - should be updated to have both forms with the same meaning. To aid in - migration, gofmt now automatically - synchronizes the two forms. For more details on the syntax and migration plan, - see - https://golang.org/design/draft-gobuild. -

- -

go run

- -

- go run now accepts arguments with version suffixes - (for example, go run - example.com/cmd@v1.0.0). This causes go - run to build and run packages in module-aware mode, ignoring the - go.mod file in the current directory or any parent directory, if - there is one. This is useful for running executables without installing them or - without changing dependencies of the current module. -

- -

Gofmt

- -

- gofmt (and go fmt) now synchronizes - //go:build lines with // +build lines. If a file - only has // +build lines, they will be moved to the appropriate - location in the file, and matching //go:build lines will be - added. Otherwise, // +build lines will be overwritten based on - any existing //go:build lines. For more information, see - https://golang.org/design/draft-gobuild. -

- -

Vet

- -

New warning for mismatched //go:build and // +build lines

- -

- The vet tool now verifies that //go:build and - // +build lines are in the correct part of the file and - synchronized with each other. If they aren't, - gofmt can be used to fix them. For more - information, see - https://golang.org/design/draft-gobuild. -

- -

New warning for calling signal.Notify on unbuffered channels

- -

- The vet tool now warns about calls to signal.Notify - with incoming signals being sent to an unbuffered channel. Using an unbuffered channel - risks missing signals sent on them as signal.Notify does not block when - sending to a channel. For example: -

- -
-c := make(chan os.Signal)
-// signals are sent on c before the channel is read from.
-// This signal may be dropped as c is unbuffered.
-signal.Notify(c, os.Interrupt)
-
- -

- Users of signal.Notify should use channels with sufficient buffer space to keep up with the - expected signal rate. -

- -

New warnings for Is, As and Unwrap methods

- -

- The vet tool now warns about methods named As, Is or Unwrap - on types implementing the error interface that have a different signature than the - one expected by the errors package. The errors.{As,Is,Unwrap} functions - expect such methods to implement either Is(error) bool, - As(interface{}) bool, or Unwrap() error - respectively. The functions errors.{As,Is,Unwrap} will ignore methods with the same - names but a different signature. For example: -

- -
-type MyError struct { hint string }
-func (m MyError) Error() string { ... } // MyError implements error.
-func (MyError) Is(target interface{}) bool { ... } // target is interface{} instead of error.
-func Foo() bool {
-	x, y := MyError{"A"}, MyError{"B"}
-	return errors.Is(x, y) // returns false as x != y and MyError does not have an `Is(error) bool` function.
-}
-
- -

Cover

- -

- The cover tool now uses an optimized parser - from golang.org/x/tools/cover, which may be noticeably faster - when parsing large coverage profiles. -

- -

Compiler

- -

- Go 1.17 implements a new way of passing function arguments and results using - registers instead of the stack. - Benchmarks for a representative set of Go packages and programs show - performance improvements of about 5%, and a typical reduction in - binary size of about 2%. - This is currently enabled for Linux, macOS, and Windows on the - 64-bit x86 architecture (the linux/amd64, - darwin/amd64, and windows/amd64 ports). -

- -

- This change does not affect the functionality of any safe Go code - and is designed to have no impact on most assembly code. - It may affect code that violates - the unsafe.Pointer - rules when accessing function arguments, or that depends on - undocumented behavior involving comparing function code pointers. - To maintain compatibility with existing assembly functions, the - compiler generates adapter functions that convert between the new - register-based calling convention and the previous stack-based - calling convention. - These adapters are typically invisible to users, except that taking - the address of a Go function in assembly code or taking the address - of an assembly function in Go code - using reflect.ValueOf(fn).Pointer() - or unsafe.Pointer will now return the address of the - adapter. - Code that depends on the value of these code pointers may no longer - behave as expected. - Adapters also may cause a very small performance overhead in two - cases: calling an assembly function indirectly from Go via - a func value, and calling Go functions from assembly. -

- -

- The format of stack traces from the runtime (printed when an uncaught panic - occurs, or when runtime.Stack is called) is improved. Previously, - the function arguments were printed as hexadecimal words based on the memory - layout. Now each argument in the source code is printed separately, separated - by commas. Aggregate-typed (struct, array, string, slice, interface, and complex) - arguments are delimited by curly braces. A caveat is that the value of an - argument that only lives in a register and is not stored to memory may be - inaccurate. Function return values (which were usually inaccurate) are no longer - printed. -

- -

- Functions containing closures can now be inlined. - One effect of this change is that a function with a closure may - produce a distinct closure code pointer for each place that the - function is inlined. - Go function values are not directly comparable, but this change - could reveal bugs in code that uses reflect - or unsafe.Pointer to bypass this language restriction - and compare functions by code pointer. -

- - - -

- When the linker uses external linking mode, which is the default - when linking a program that uses cgo, and the linker is invoked - with a -I option, the option will now be passed to the - external linker as a -Wl,--dynamic-linker option. -

- -

Core library

- -

Cgo

- -

- The runtime/cgo package now provides a - new facility that allows to turn any Go values to a safe representation - that can be used to pass values between C and Go safely. See - runtime/cgo.Handle for more information. -

- -

URL query parsing

- - -

- The net/url and net/http packages used to accept - ";" (semicolon) as a setting separator in URL queries, in - addition to "&" (ampersand). Now, settings with non-percent-encoded - semicolons are rejected and net/http servers will log a warning to - Server.ErrorLog - when encountering one in a request URL. -

- -

- For example, before Go 1.17 the Query - method of the URL example?a=1;b=2&c=3 would have returned - map[a:[1] b:[2] c:[3]], while now it returns map[c:[3]]. -

- -

- When encountering such a query string, - URL.Query - and - Request.FormValue - ignore any settings that contain a semicolon, - ParseQuery - returns the remaining settings and an error, and - Request.ParseForm - and - Request.ParseMultipartForm - return an error but still set Request fields based on the - remaining settings. -

- -

- net/http users can restore the original behavior by using the new - AllowQuerySemicolons - handler wrapper. This will also suppress the ErrorLog warning. - Note that accepting semicolons as query separators can lead to security issues - if different systems interpret cache keys differently. - See issue 25192 for more information. -

- -

TLS strict ALPN

- - -

- When Config.NextProtos - is set, servers now enforce that there is an overlap between the configured - protocols and the ALPN protocols advertised by the client, if any. If there is - no mutually supported protocol, the connection is closed with the - no_application_protocol alert, as required by RFC 7301. This - helps mitigate the ALPACA cross-protocol attack. -

- -

- As an exception, when the value "h2" is included in the server's - Config.NextProtos, HTTP/1.1 clients will be allowed to connect as - if they didn't support ALPN. - See issue 46310 for more information. -

- -

Minor changes to the library

- -

- As always, there are various minor changes and updates to the library, - made with the Go 1 promise of compatibility - in mind. -

- -
archive/zip
-
-

- The new methods File.OpenRaw, Writer.CreateRaw, Writer.Copy provide support for cases where performance is a primary concern. -

-
-
- -
bufio
-
-

- The Writer.WriteRune method - now writes the replacement character U+FFFD for negative rune values, - as it does for other invalid runes. -

-
-
- -
bytes
-
-

- The Buffer.WriteRune method - now writes the replacement character U+FFFD for negative rune values, - as it does for other invalid runes. -

-
-
- -
compress/lzw
-
-

- The NewReader - function is guaranteed to return a value of the new - type Reader, - and similarly NewWriter - is guaranteed to return a value of the new - type Writer. - These new types both implement a Reset method - (Reader.Reset, - Writer.Reset) - that allows reuse of the Reader or Writer. -

-
-
- -
crypto/ed25519
-
-

- The crypto/ed25519 package has been rewritten, and all - operations are now approximately twice as fast on amd64 and arm64. - The observable behavior has not otherwise changed. -

-
-
- -
crypto/elliptic
-
-

- CurveParams - methods now automatically invoke faster and safer dedicated - implementations for known curves (P-224, P-256, and P-521) when - available. Note that this is a best-effort approach and applications - should avoid using the generic, not constant-time CurveParams - methods and instead use dedicated - Curve implementations - such as P256. -

- -

- The P521 curve - implementation has been rewritten using code generated by the - fiat-crypto project, - which is based on a formally-verified model of the arithmetic - operations. It is now constant-time and three times faster on amd64 and - arm64. The observable behavior has not otherwise changed. -

-
-
- -
crypto/rand
-
-

- The crypto/rand package now uses the getentropy - syscall on macOS and the getrandom syscall on Solaris, - Illumos, and DragonFlyBSD. -

-
-
- -
crypto/tls
-
-

- The new Conn.HandshakeContext - method allows the user to control cancellation of an in-progress TLS - handshake. The provided context is accessible from various callbacks through the new - ClientHelloInfo.Context and - CertificateRequestInfo.Context - methods. Canceling the context after the handshake has finished has no effect. -

- -

- Cipher suite ordering is now handled entirely by the - crypto/tls package. Currently, cipher suites are sorted based - on their security, performance, and hardware support taking into account - both the local and peer's hardware. The order of the - Config.CipherSuites - field is now ignored, as well as the - Config.PreferServerCipherSuites - field. Note that Config.CipherSuites still allows - applications to choose what TLS 1.0–1.2 cipher suites to enable. -

- -

- The 3DES cipher suites have been moved to - InsecureCipherSuites - due to fundamental block size-related - weakness. They are still enabled by default but only as a last resort, - thanks to the cipher suite ordering change above. -

- -

- Beginning in the next release, Go 1.18, the - Config.MinVersion - for crypto/tls clients will default to TLS 1.2, disabling TLS 1.0 - and TLS 1.1 by default. Applications will be able to override the change by - explicitly setting Config.MinVersion. - This will not affect crypto/tls servers. -

-
-
- -
crypto/x509
-
-

- CreateCertificate - now returns an error if the provided private key doesn't match the - parent's public key, if any. The resulting certificate would have failed - to verify. -

- -

- The temporary GODEBUG=x509ignoreCN=0 flag has been removed. -

- -

- ParseCertificate - has been rewritten, and now consumes ~70% fewer resources. The observable - behavior has not otherwise changed, except for error messages. -

- -

- On BSD systems, /etc/ssl/certs is now searched for trusted - roots. This adds support for the new system trusted certificate store in - FreeBSD 12.2+. -

- -

- Beginning in the next release, Go 1.18, crypto/x509 will - reject certificates signed with the SHA-1 hash function. This doesn't - apply to self-signed root certificates. Practical attacks against SHA-1 - have been demonstrated in 2017 and publicly - trusted Certificate Authorities have not issued SHA-1 certificates since 2015. -

-
-
- -
database/sql
-
-

- The DB.Close method now closes - the connector field if the type in this field implements the - io.Closer interface. -

- -

- The new - NullInt16 - and - NullByte - structs represent the int16 and byte values that may be null. These can be used as - destinations of the Scan method, - similar to NullString. -

-
-
- -
debug/elf
-
-

- The SHT_MIPS_ABIFLAGS - constant has been added. -

-
-
- -
encoding/binary
-
-

- binary.Uvarint will stop reading after 10 bytes to avoid - wasted computations. If more than 10 bytes are needed, the byte count returned is -11. -
- Previous Go versions could return larger negative counts when reading incorrectly encoded varints. -

-
-
- -
encoding/csv
-
-

- The new - Reader.FieldPos - method returns the line and column corresponding to the start of - a given field in the record most recently returned by - Read. -

-
-
- -
encoding/xml
-
-

- When a comment appears within a - Directive, it is now replaced - with a single space instead of being completely elided. -

- -

- Invalid element or attribute names with leading, trailing, or multiple - colons are now stored unmodified into the - Name.Local field. -

-
-
- -
flag
-
-

- Flag declarations now panic if an invalid name is specified. -

-
-
- -
go/build
-
-

- The new - Context.ToolTags - field holds the build tags appropriate to the current Go - toolchain configuration. -

-
-
- -
go/format
-
-

- The Source and - Node functions now - synchronize //go:build lines with // +build - lines. If a file only has // +build lines, they will be - moved to the appropriate location in the file, and matching - //go:build lines will be added. Otherwise, - // +build lines will be overwritten based on any existing - //go:build lines. For more information, see - https://golang.org/design/draft-gobuild. -

-
-
- -
go/parser
-
-

- The new SkipObjectResolution - Mode value instructs the parser not to resolve identifiers to - their declaration. This may improve parsing speed. -

-
-
- -
image
-
-

- The concrete image types (RGBA, Gray16 and so on) - now implement a new RGBA64Image - interface. The concrete types that previously implemented - draw.Image now also implement - draw.RGBA64Image, a - new interface in the image/draw package. -

-
-
- -
io/fs
-
-

- The new FileInfoToDirEntry function converts a FileInfo to a DirEntry. -

-
-
- -
math
-
-

- The math package now defines three more constants: MaxUint, MaxInt and MinInt. - For 32-bit systems their values are 2^32 - 1, 2^31 - 1 and -2^31, respectively. - For 64-bit systems their values are 2^64 - 1, 2^63 - 1 and -2^63, respectively. -

-
-
- -
mime
-
-

- On Unix systems, the table of MIME types is now read from the local system's - Shared MIME-info Database - when available. -

-
-
- -
mime/multipart
-
-

- Part.FileName - now applies - filepath.Base to the - return value. This mitigates potential path traversal vulnerabilities in - applications that accept multipart messages, such as net/http - servers that call - Request.FormFile. -

-
-
- -
net
-
-

- The new method IP.IsPrivate reports whether an address is - a private IPv4 address according to RFC 1918 - or a local IPv6 address according RFC 4193. -

- -

- The Go DNS resolver now only sends one DNS query when resolving an address for an IPv4-only or IPv6-only network, - rather than querying for both address families. -

- -

- The ErrClosed sentinel error and - ParseError error type now implement - the net.Error interface. -

- -

- The ParseIP and ParseCIDR - functions now reject IPv4 addresses which contain decimal components with leading zeros. - - These components were always interpreted as decimal, but some operating systems treat them as octal. - This mismatch could hypothetically lead to security issues if a Go application was used to validate IP addresses - which were then used in their original form with non-Go applications which interpreted components as octal. Generally, - it is advisable to always re-encode values after validation, which avoids this class of parser misalignment issues. -

-
-
- -
net/http
-
-

- The net/http package now uses the new - (*tls.Conn).HandshakeContext - with the Request context - when performing TLS handshakes in the client or server. -

- -

- Setting the Server - ReadTimeout or WriteTimeout fields to a negative value now indicates no timeout - rather than an immediate timeout. -

- -

- The ReadRequest function - now returns an error when the request has multiple Host headers. -

- -

- When producing a redirect to the cleaned version of a URL, - ServeMux now always - uses relative URLs in the Location header. Previously it - would echo the full URL of the request, which could lead to unintended - redirects if the client could be made to send an absolute request URL. -

- -

- When interpreting certain HTTP headers handled by net/http, - non-ASCII characters are now ignored or rejected. -

- -

- If - Request.ParseForm - returns an error when called by - Request.ParseMultipartForm, - the latter now continues populating - Request.MultipartForm - before returning it. -

-
-
- -
net/http/httptest
-
-

- ResponseRecorder.WriteHeader - now panics when the provided code is not a valid three-digit HTTP status code. - This matches the behavior of ResponseWriter - implementations in the net/http package. -

-
-
- -
net/url
-
-

- The new method Values.Has - reports whether a query parameter is set. -

-
-
- -
os
-
-

- The File.WriteString method - has been optimized to not make a copy of the input string. -

-
-
- -
reflect
-
-

- The new - Value.CanConvert - method reports whether a value can be converted to a type. - This may be used to avoid a panic when converting a slice to an - array pointer type if the slice is too short. - Previously it was sufficient to use - Type.ConvertibleTo - for this, but the newly permitted conversion from slice to array - pointer type can panic even if the types are convertible. -

- -

- The new - StructField.IsExported - and - Method.IsExported - methods report whether a struct field or type method is exported. - They provide a more readable alternative to checking whether PkgPath - is empty. -

- -

- The new VisibleFields function - returns all the visible fields in a struct type, including fields inside anonymous struct members. -

- -

- The ArrayOf function now panics when - called with a negative length. -

- -

- Checking the Type.ConvertibleTo method - is no longer sufficient to guarantee that a call to - Value.Convert will not panic. - It may panic when converting `[]T` to `*[N]T` if the slice's length is less than N. - See the language changes section above. -

-
-
- -
runtime/metrics
-
-

- New metrics were added that track total bytes and objects allocated and freed. - A new metric tracking the distribution of goroutine scheduling latencies was - also added. -

-
-
- -
runtime/pprof
-
-

- Block profiles are no longer biased to favor infrequent long events over - frequent short events. -

-
-
- -
strconv
-
-

- The strconv package now uses Ulf Adams's Ryū algorithm for formatting floating-point numbers. - This algorithm improves performance on most inputs and is more than 99% faster on worst-case inputs. -

- -

- The new QuotedPrefix function - returns the quoted string (as understood by - Unquote) - at the start of input. -

-
-
- -
strings
-
-

- The Builder.WriteRune method - now writes the replacement character U+FFFD for negative rune values, - as it does for other invalid runes. -

-
-
- -
sync/atomic
-
-

- atomic.Value now has Swap and - CompareAndSwap methods that provide - additional atomic operations. -

-
-
- -
syscall
-
-

-

- The GetQueuedCompletionStatus and - PostQueuedCompletionStatus - functions are now deprecated. These functions have incorrect signatures and are superseded by - equivalents in the golang.org/x/sys/windows package. -

- -

- On Unix-like systems, the process group of a child process is now set with signals blocked. - This avoids sending a SIGTTOU to the child when the parent is in a background process group. -

- -

- The Windows version of - SysProcAttr - has two new fields. AdditionalInheritedHandles is - a list of additional handles to be inherited by the new child - process. ParentProcess permits specifying the - parent process of the new process. - -

- The constant MSG_CMSG_CLOEXEC is now defined on - DragonFly and all OpenBSD systems (it was already defined on - some OpenBSD systems and all FreeBSD, NetBSD, and Linux systems). -

- -

- The constants SYS_WAIT6 and WEXITED - are now defined on NetBSD systems (SYS_WAIT6 was - already defined on DragonFly and FreeBSD systems; - WEXITED was already defined on Darwin, DragonFly, - FreeBSD, Linux, and Solaris systems). -

-
-
- -
testing
-
-

- Added a new testing flag -shuffle which controls the execution order of tests and benchmarks. -

-

- The new - T.Setenv - and B.Setenv - methods support setting an environment variable for the duration - of the test or benchmark. -

-
-
- -
text/template/parse
-
-

- The new SkipFuncCheck Mode - value changes the template parser to not verify that functions are defined. -

-
-
- -
time
-
-

- The Time type now has a - GoString method that - will return a more useful value for times when printed with the - %#v format specifier in the fmt package. -

- -

- The new Time.IsDST method can be used to check whether the time - is in Daylight Savings Time in its configured location. -

- -

- The new Time.UnixMilli and - Time.UnixMicro - methods return the number of milliseconds and microseconds elapsed since - January 1, 1970 UTC respectively. -
- The new UnixMilli and - UnixMicro functions - return the local Time corresponding to the given Unix time. -

- -

- The package now accepts comma "," as a separator for fractional seconds when parsing and formatting time. - For example, the following time layouts are now accepted: -

    -
  • 2006-01-02 15:04:05,999999999 -0700 MST
    • -
  • Mon Jan _2 15:04:05,000000 2006
    • -
  • Monday, January 2 15:04:05,000 2006
    • -
-

- -

- The new constant Layout - defines the reference time. -

-
-
- -
unicode
-
-

- The Is, - IsGraphic, - IsLetter, - IsLower, - IsMark, - IsNumber, - IsPrint, - IsPunct, - IsSpace, - IsSymbol, and - IsUpper functions - now return false on negative rune values, as they do for other invalid runes. -

-
-
diff --git a/doc/go1.18.html b/doc/go1.18.html new file mode 100644 index 0000000000..2dc4c1427d --- /dev/null +++ b/doc/go1.18.html @@ -0,0 +1,84 @@ + + + + + + +

DRAFT RELEASE NOTES — Introduction to Go 1.18

+ +

+ + Go 1.18 is not yet released. These are work-in-progress + release notes. Go 1.18 is expected to be released in February 2022. + +

+ +

Changes to the language

+ +

+ TODO: complete this section +

+ +

Ports

+ +

+ TODO: complete this section, or delete if not needed +

+ +

Tools

+ +

+ TODO: complete this section, or delete if not needed +

+ +

Go command

+ +

+ TODO: complete this section, or delete if not needed +

+ +

Runtime

+ +

+ TODO: complete this section, or delete if not needed +

+ +

Compiler

+ +

+ TODO: complete this section, or delete if not needed +

+ +

Linker

+ +

+ TODO: complete this section, or delete if not needed +

+ +

Core library

+ +

+ TODO: complete this section +

+ +

Minor changes to the library

+ +

+ As always, there are various minor changes and updates to the library, + made with the Go 1 promise of compatibility + in mind. +

+ +

+ TODO: complete this section +

-- 2.48.1